The champions came close to an embarrassing exit as they surrendered a three-goal lead and on this form, no side will fear them in the semi-finals
The unthinkable almost happened again. After Barcelona let a 4-1 first-leg lead slip away to Roma on Tuesday to crash out of the Champions League in humiliating fashion, Real Madrid almost followed them with an even worse capitulation on Wednesday.
Zinedine Zidane's side had thrashed Juventus 3-0 in Turin and looked likely to cruise into the semi-finals in a home leg that appeared a formality, almost a dead rubber. But if Tuesday night's action showed us anything, it is that these ties are far from over at the halfway stage.
Like Barca and also Liverpool against City on Tuesday, Madrid conceded an early goal as Mario Mandzukic converted inside a minute and a half. And the Croatia striker scored again before half-time to make the home fans very nervous indeed.
That is how quickly a tie can turn on its head in the Champions League and, suddenly, the defending champions were running the risk of catastrophe against a Juve side with absolutely nothing to lose.
This was reminiscent of Madrid's Dortmund defeat en route to the 2014 Champions League crown, when Carlo Ancelotti's side lost 2-0 in Germany after winning the first match 3-0 in Madrid.